AP BIOLOGY

Detailed explanation-1: -Denitrification completes the nitrogen cycle by converting nitrate (NO3-) back to gaseous nitrogen (N2). Denitrifying bacteria are the agents of this process. These bacteria use nitrate instead of oxygen when obtaining energy, releasing nitrogen gas to the atmosphere.

Detailed explanation-2: -Denitrification is the process that converts nitrate to nitrogen gas, thus removing bioavailable nitrogen and returning it to the atmosphere. Dinitrogen gas (N2) is the ultimate end product of denitrification, but other intermediate gaseous forms of nitrogen exist (Figure 7).

Detailed explanation-3: -Ammonification of this nitrogenous waste by bacteria and fungi in the soil converts the organic nitrogen to ammonium ion-NH4 plus. Ammonium is converted to nitrit-NO2 minus-then to nitrate-NO3 minus-by nitrifying bacteria. Denitrifying bacteria convert the nitrate back into nitrogen gas, which reenters the atmosphere.

Detailed explanation-4: -Denitrification is the process during which the nitrogen compound is released back into the atmosphere by converting nitrate (NO3-) into gaseous nitrogen (N). The process of denitrification is carried out during the absence of oxygen by Thiobacillus species and Pseudomonas bacteria present in the soil.

Detailed explanation-5: -Nitrogen returns to the soil when organisms release waste or die and are decomposed by bacteria and fungi. Nitrogen is released back to the atmosphere by bacteria get their energy by breaking down nitrate and nitrite into nitrogen gas (also called denitrification).